UEFI - Unified Extensible Firmware Interface

How UEFI Will Change The Boot Process Of A Personal Computer


When you first turn on your computer system, it doesn't immediately start loading your operating system. It goes through a routine that was originally established with the first personal computers by initiating the hardware through the Basic Input Output System or BIOS. This is required to allow the computer's various hardware components to properly communicate with one another. Once the Power On Self Test or POST is completed, the BIOS then initiates the actual operating system boot loader.

This processor has essentially remained the same for over twenty years but consumers might not realize that this has changed in the past couple of years. Most computers now use a system called the Unified Extensible Firmware Interface or UEFI. This article takes a look at what this is and what it means to personal computers.

History Of UEFI

UEFI is actually an extension of the original Extensible Firmware Interface developed by Intel. They developed this new hardware and software interface system when they launched the ill fated Itanium or IA64 server processor lineup. Because of its advanced architecture and the limitations of the existing BIOS systems, they wanted to develop a new method for handing off the hardware to the operating system that would allow for greater flexibility. Because the Itanium wasn't a huge success, the EFI standards also languished for many years.

In 2005, the Unified EFI Forum was established between a number of major corporations that would expand upon the original specifications developed by Intel to produce a new standard for updating the hardware and software interface.

This includes companies such as AMD, Apple, Dell, HP, IBM, Intel, Lenovo and Microsoft. Even two of the largest BIOS makers, American Megatrends Inc. and Pheonix Technologies are members.

What Is UEFI?

The UEFI is a specification that defines how the hardware and software communicate within a computer system.

The specification actually involves two aspects of this process known as boot services and runtime services. The boot services defines how the hardware will initiate the software or operating system for loading. Runtime services involves actually skipping the boot processor and loading applications directly from the UEFI. This makes it act somewhat like a striped down operating system by launching a browser.

While many call UEFI the death of BIOS, the system actually does not completely remove the BIOS from the hardware. The early specifications lacked any of the POST or configuration options. As a result, the system still requires the BIOS in order to achieve these two goals. The difference is that the BIOS will likely not have the same level of adjustment as is possible in existing BIOS only systems.

Benefits Of UEFI

The biggest benefit of UEFI is the lack of any specific hardware dependence. BIOS is specific to the x86 architecture that has been used in PCs for years. This potentially allows for a personal computer to use a processor from a different vendor or that does not have the legacy x86 coding in it. This could have implications to devices like tablets or even Microsoft's ultimately doomed Surface with Windows RT that used an ARM based processor.

The other major benefit to the UEFI is the ability to easily launch into multiple operating systems without a need of a bootloader such as LILO or GRUB. Instead, the UEFI can automatically select the appropriate partition with the operating system and load from it. In order for this to be achieved though, both the hardware and the software must have the appropriate support for the UEFI specification. This actually already exists in Apple's computer systems that use Boot Camp to have either Mac OS X and Windows load on the same computer.

Finally, the UEFI will offer much more user friendly interfaces than the old text menus of the BIOS. This will make adjustments to the system much easier for the end user to make. In addition, the interface will likely allow for applications such as a limited use web browser or mail client to be launched quickly rather than launching a full OS. Now, some computers have this ability but it is actually achieved by launching a separate mini operating system that is housed within the BIOS.

Drawbacks Of UEFI

The biggest issue for consumers with UEFI is hardware and software support. In order for it to work properly, the hardware and operating system must both support the appropriate specification. This isn't as much of an issue with the current Windows or Mac OS X right now but older operating systems such as Windows XP do not support this. The problem actually is more of the reverse. Instead, newer software that requires UEFI systems may prevent older systems from upgrading to newer operating systems.

Many power users who overclock their computer systems may also be disappointed. The addition of UEFI removes many of the various settings within the BIOS used to get the most performance out of a processor and memory as possible. This was mostly a problem with the first generation of UEFI hardware. It is true that most hardware not designed for overclocking will lack features such a voltage or multiplier adjustments but most new hardware designed for this have overcome these issues.


BIOS has been extremely effective at running personal computers for the past twenty plus years. It has reached a number of limitations that make it hard to continue creating new technologies without introducing more workarounds for the issues. UEFI is set to take over much of the process from the BIOS and streamline it for the end user. This will make the computing environment easier to use and create a much more flexible environment. The introduction of the technology won't be without its problems but the potential greatly outweigh the legacy requirements inherent to an all BIOS computer.

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